Pro football’s head injury problem is real, it’s serious, and the National Football League needs to take a leadership role in addressing it in a way that makes America’s most popular sport one of its safest.

In the last 20 years or so, study after study has shown that football players who suffered multiple concussions in their careers were at risk of developing a degenerative brain disease called chronic traumatic encephalopathy, or CTE. The effects are not pretty, and include confusion, depression and dementia, and a frighteningly increased risk of suicide.

The latest study, released last week by Boston University, found that 110 of the 111 brains—99 percent—of deceased former NFL players examined tested positive for the disease. The numbers were almost as high for college players, 48 of 53—91 percent—tested positive.

With training camps now open ahead of the new season, and high school and college teams gearing up for their fall schedule, the issue is even more urgent. Indeed, football’s longtime survival may very well depend on the priority given to player safety.

Concerns over CTE have already left their mark. A number of NFL players have retired early, and many parents no longer want their kids playing youth games because they fear the long-term effects of repeated head injuries. To counteract declining enrollment, and to protect its young players, the Pop Warner League, the country’s largest youth football organization, announced last year that it would ban kickoffs—considered one of the most dangerous plays—from its three youngest divisions and would consider extending the policy to older divisions as well.

That’s certainly a positive step by the youth league, and an example of some of the dramatic changes that football needs to make it safer.

It’s not as though the NFL has done nothing to address the problem. Over the years, it has funded major research into brain injuries and agreed to pay $765 million, later raised to $1 billion, in a hard-fought lawsuit to pay claims of former players who charged that the league covered up the dangers.

Still, more research and a lot more resolve are needed. One of the most obvious places to look is at helmets. Can something be developed that can better absorb blows to the head? If so, should they be required equipment?

Another place to look for answers is on the playing fields, and the impact-absorbing qualities of natural versus synthetic fields. Some studies have suggested that specialized compression collars can help, others see better mouth guards as useful. There’s even a school of thought that advocates holding practice without helmets as a way to heighten players’ awareness of possible injuries and how to avoid them.

Certainly, the NFL’s protocol on evaluating players for concussions during games and practice needs to be stringently followed and strengthened if necessary.

There’s no easy solution. But the players are the league’s most valuable assets, and they’re beloved by millions of fans. They need and deserve the protection of the NFL.

That’s why we urge the NFL to make player health and safety the number one concern of the league. There is no more important priority.